Research on modular electromechanical transient modeling of UPFC based on VSC

This paper presents an efficient modular electromechanical transient modeling method of unified power flow controller (UPFC) based on voltage source converter (VSC). The most distinctive advantage of the modeling method proposed in this paper is that it can be applied to the simulation of different UPFC structures and access ways. This method is based on basic VSC-based UPFC rules. Firstly, transform different VSC topology structures into unified and equivalent current circuit. Next, divide UPFC into four modules: series module, parallel module, DC module and control module. Then, calculate each module in turn. Finally, solve the UPFC part and the network equation alternately until the convergence is reached. This modeling method has already been applied and proved effective in “PSD” power system analysis tools. The accuracy of the model is verified by the example analysis and the comparison with the Real Time Digital Simulator (RTDS) dynamic test curve.